Abstract: The Eastern Black Sea region (NE Türkiye) has important geological, historical, and natural value. The geological setting of the region includes the Paleozoic, Mesozoic, and Cenozoic periods. From a palaeobiological point of view, there have been five major extinction events since the formation of the Earth. Studies of the Cretaceous/Paleogene transition/extinction 66 million years ago (mainly platinum group element anomalies, Mg/Ca ratios, Srisotopes, C-O stable isotopes, and biostratigraphy) have identified the K/Pg boundary/transition markers in detail. In particular, the Eastern Black Sea region has a large Mesozoic-Cenozoic stratigraphic mass. Sedimentary rocks, which are fewer than the igneous and volcanic rocks, also outcrop in the region. These sedimentary rocks, therefore,provide insights in to the biostratigraphy of the region. K/Pg-aged neritic and pelagic sequences are distributed along the Black Sea on an east-west axis. The K/Pg transition in the sequences is indicated to be neritic-neritic at Ordu,pelagic-pelagic and neritic-neritic at Trabzon, and pelagic-pelagic and neritic-neritic at Artvin. These transitions were identified from foraminiferal biostratigraphy according to benthic Orbitoides-Lepidorbitoides and plankticG. gansseri-A. mayaroensis in the Late Cretaceous and benthic Shallow Benthic Zone (SBZ) 1-3 and planktic P0-P5 biozones in the Paleogene. Especially in the K/Pg transition/boundary in neritic sediments in the Ordu region; Orduina erki gen. n. sp. (Sirel, 1969), Laffitteina erki (Sirel, 1994), Orduella sphaerica n. gen. n. sp. (Sirel, 1999),Selimina spinalis n. gen. n. sp. (İnan, 1996), Sirelina orduensis n. gen. n. sp. (Meriç and İnan, 1998), and Cocoarotaorali n. sp. (İnan, 2003) were identified as new genus and species. In this distribution, K/Pg outcrop sections occur inOrdu, Trabzon, and Artvin. Based on the biostratigraphic data, it was determined that the successions in these three regions, which contain the transition between the Cretaceous and the Paleogene, are important palaeobiological geosites for both Türkiye and the world.